The 20-year yield lost half a basis point to 0.350 percent. The 30-year yield and the 40-year yield dipped 1 basis point each, to 0.525 percent and 0.550 percent, respectively.

Ten-year JGB futures tacked on 0.06 point to 152.94, with a trading volume of 12,247 lots by mid-afternoon trade.

The Bank of Japan offered to buy 480 billion yen ($4.32 billion) of five- to 10-year bonds in a regular debt-purchasing operation, providing support to the broader market.

Japan's Nikkei lost 0.7 percent, dropping to a one-week low, after US President Donald Trump said he would impose tariffs on $11 billion of European goods.